Caffeine

Caffeine can be found naturally in the leaves, seeds, or fruits of over 60 plants. These include coffee beans, cacao beans, kola nuts, guarana berries, and tea leaves including yerbe matte and green tea. Caffeine is commonly used as a stimulant which serves to increase nervous system activity leading to increased energy and alertness. It also belongs to the drug class known as xanthenes along with cardiac stimulants and theophylline (found in tea and other substances) and theobromine (found in chocolate and other substances). Caffeine is the only stimulant considered safe by the U.S. FDA for use in over-the-counter medications.[1]

Exercise Performance: Caffeine has long been used as an ergogenic aid, or aid to increase performance. It appears to work best for activities of moderate intensity and longer duration. It increases heart rate, respiratory rate, and blood pressure. Caffeine also changes the metabolism of cells by increasing the breakdown of fat and inhibiting the breakdown of glycogen (the storage form of glucose). This shift means that the body is using fat to create energy and conserves glycogen stores, increasing endurance. Caffeine appears to aid in activities such as running, cross-country skiing, and cycling- all activities of longer duration and moderate intensity. Doses may vary depending on a person's intake of caffeine on a regular basis, higher doses being necessary for the more habitual coffee drinker, for instance. Furthermore, the anxiety provoking effects of caffeine may be attenuated by exercise. These positive benefits of caffeine can be achieved at levels that are within legal limits according to the International Olympic Committee, but one should always use ergogenic aids with caution when enhancing performance at a competitive level [2].

Cognitive performance and mood: Caffeine is commonly used by many people as a means to boost alertness in order to perform a demanding task requiring mental stamina. According to one study, L-theanine (a non-protein amino acid) and caffeine (both found naturally in tea) at doses of 97mg and 40mg respectively helped to improve accuracy during task switching and subjective alertness and reduced fatigue.[3]

Respiratory disorders: Caffeine has been shown to have a broncodilatory effect meaning that it opens the airways. It also reduces respiratory muscle fatigue. For these reasons, it has been considered for the treatment of asthmatic episodes. A 2010 Cochrane review concluded that caffeine modestly improves airway function for up to 4 hours in asthmatic individuals [4] In a study comparing caffeine and albuterol (short-acting beta-2 agonist used for asthma) and their effectiveness in treating exercise-induced asthmatic episodes, caffeine at moderate to high doses taken before exercise was found to provide protection from such episodes. It is also proposed as a suitable agent to aid in the reduction of daily use of short-acting beta-2 agonists which have some negative side effects [5]

Apnea in Infants: Apneic episodes are common in preterm infants, causing low blood oxygen and slowed heart rate which can be severe enough to require ventilation assistance. According to a 2010 Cochrane review, caffeine is an effective treatment for infant apnea in preterm infants with better longer term outcomes. It appears to be safer than other methylxanthine drugs such as theophylline and aminophylline.[6].

Because it is a diuretic, it can also cause a deficiency in nutrients that are needed for sleep such as B vitamins, calcium, magnesium, zinc, and iron.[8]

Prescribing Considerations

The recommended dosages varies based on age and health status. To determine what your specific requirements are talk to your naturopathic doctor or other trained medical professional.

Child and Adolescent: A typical therapeutic oral dose ranges from 80-300mg. Higher doses have also been used.

Adult: A typical oral dose ranges from 200-400mg but it is dependent on body weight; some conditions warrant doses that are much higher.

Pregnancy and Lactation: Caffeine is not recommended at this time.

An 8 ounce cup of regular brewed coffee contains 65-120mg of caffeine. An 8 ounce cup of brewed tea has about 20-90mg.

Safety

General Adverse Effects

The effects are brief as caffeine is typically metabolized and cleared within a few hours, adverse effects may include dehydration, hypertension, palpitations, increased heart rate, gastrointestinal disturbances, jitteriness, restlessness, nervousness, sleep disturbances, and increased urination.

Children: Not recommended for general use in children.

Adults: Moderate consumption is considered safe in most adults (100-200mg/day).

Pregnancy Breastfeeding

Caffeine is not recommended at this time as it can cause spontaneous abortion and low birthweight. It can also be transferred into breast milk, causing anxiety in infants who are breastfeeding. However, in women who do consume caffeine during pregnancy and nursing, it should not exceed 200mg/day.